Semiconductor constructions

ABSTRACT

Some embodiments include DRAM having transistor gates extending partially over SOI, and methods of forming such DRAM. Unit cells of the DRAM may be within active region pedestals, and in some embodiments the unit cells may comprise capacitors having storage nodes in direct contact with sidewalls of the active region pedestals. Some embodiments include OCIT memory having transistor gates entirely over SOI, and methods of forming such OCIT memory.

TECHNICAL FIELD

Memory arrays, semiconductor constructions and electronic systems; andmethods of forming memory arrays, semiconductor constructions andelectronic systems.

BACKGROUND

Integrated circuitry may include arrays of memory devices for datastorage. The memory devices may, for example, be dynamic random accessmemory (DRAM) devices; with the DRAM unit cells corresponding totransistors coupled with charge storage devices (typically capacitors).Alternatively, the memory devices may lack the capacitors of DRAM. Suchmemory may be referred to as zero-capacitor-one-transistor (OCIT)memory, and may correspond to so-called ZRAM™ (zero capacitance DRAM).

A continuing goal of integrated circuit fabrication is to increase thelevel of integration; with a corresponding goal to decrease the size ofmemory devices, to simplify memory devices, and/or to reduce thecomplexity and amount of wiring associated with memory devices. Anothercontinuing goal of integrated circuit fabrication is to reduce thenumber of steps of a fabrication process, thereby improving throughputand possibly reducing costs.

One approach being utilized to increase integration is to incorporatepartially-insulated transistors into memory devices. More specifically,the approach is to utilize partial semiconductor on insulator (SOI) toalleviate leakage at source/drain junctions of transistor devices. Theindividual transistor devices comprise a gate, and a pair ofsource/drain regions on opposing sides of the gate. The source/drainregions extend within a first semiconductor material, and have insulatordirectly beneath them which isolates them from a bulk semiconductormaterial beneath the first semiconductor material. The insulatorprovided beneath the source/drain regions does not extend under thetransistor gate to any substantial degree.

It is desired to develop improved memory devices, and improved methodsfor fabricating memory devices. Although some embodiments disclosedherein were motivated, at least in part, by such a desire, otherembodiments may have applications beyond memory device structures andfabrication.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are a diagrammatic fragmentary top view and across-sectional side view, respectively, of portions of a semiconductorconstruction at a processing stage in accordance with an embodiment. Thecross-section of FIG. 2 is along the line 2-2 of FIG. 1.

FIGS. 3 and 4 are views of the portions of FIGS. 1 and 2, respectively,at a processing stage subsequent to that of FIGS. 1 and 2. Thecross-section of FIG. 4 is along the line 4-4 of FIG. 3.

FIGS. 5 and 6 are views of the portions of FIGS. 1 and 2, respectively,at a processing stage subsequent to that of FIGS. 3 and 4. Thecross-section of FIG. 6 is along the line 6-6 of FIG. 5.

FIGS. 7 and 8 are views of the portions of FIGS. 1 and 2, respectively,at a processing stage subsequent to that of FIGS. 5 and 6. Thecross-section of FIG. 8 is along the line 8-8 of FIG. 7.

FIGS. 9-11 are views of the construction of FIGS. 1 and 2 at aprocessing stage subsequent to that of FIGS. 7 and 8. FIGS. 9 and 10 areviews of the portions of FIGS. 1 and 2, respectively, and FIG. 11 is aview along a cross-section substantially orthogonal to that of FIG. 10.The cross-section of FIG. 10 is along the lines 10-10 of FIGS. 9 and 11;and the cross-section of FIG. 11 is along the lines 11-11 of FIGS. 9 and10.

FIGS. 12 and 13 are views of the portions of FIGS. 1 and 2,respectively, at a processing stage subsequent to that of FIGS. 9-11,The cross-section of FIG. 13 is along the line 13-13 of FIG. 12.

FIGS. 14 and 15 are views of the portions of FIGS. 1 and 2,respectively, at a processing stage subsequent to that of FIGS. 12 and13, The cross-section of FIG. 15 is along the line 15-15 of FIG. 14.

FIGS. 16-18 are views of the portions of FIGS. 9-11 at a processingstage subsequent to that of FIGS. 14 and 15. The cross-section of FIG.17 is along the lines 17-17 of FIGS. 16 and 18; and the cross-section ofFIG. 18 is along the lines 18-18 of FIGS. 16 and 17.

FIGS. 19-21 are views of the portions of FIGS. 9-11 at a processingstage subsequent to that of FIGS. 16-18. The cross-section of FIG. 20 isalong the lines 20-20 of FIGS. 19 and 21; and the cross-section of FIG.21 is along the lines 21-21 of FIGS. 19 and 20.

FIGS. 22-24 are views of the portions of FIGS. 9-11 at a processingstage subsequent to that of FIGS. l 19-21. The cross-section of FIG. 23is along the lines 23-23 of FIGS. 22. and 24; and the cross-section ofFIG. 24 is along the lines 24-24 of FIGS. 22 and 23.

FIG. 25 is a view of the portion of FIG. 2 at a processing stagesubsequent to that of FIGS. 22-24.

FIG. 26 is a cross-sectional view of a portion of a semiconductorconstruction at the processing stage of FIG. 25, with the cross-sectionof FIG. 26 being offset relative to that of FIG. 25. FIG. 26 correspondsto a cross-section that would be out of the page relative to thecross-section of FIG. 25.

FIG. 27 is a view of the portion of FIG. 2 at a processing stageanalogous to that of FIG. 25, in accordance with another embodiment.

FIG. 28 is a diagrammatic view of a computer embodiment.

FIG. 29 is a block diagram showing particular features of themotherboard of the FIG. 27 computer embodiment.

FIG. 30 is a high level block diagram of an electronic systemembodiment.

FIG. 31 is a simplified block diagram of a memory device embodiment.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Some embodiments include utilization of partial SOI in transistordevices. The transistor devices may be utilized in DRAM. The transistordevices have insulator extending under a storage node and partiallyunder a transistor gate. A region beneath the transistor gate which isnot blocked by insulator may be utilized as a tie between the channel ofthe transistor and a semiconductor body, while the region which isblocked may alleviate, and in some embodiments prevent, leakage from thestorage node back across the access device (so-called gate off-stateleakage). In some embodiments, the transistor may be utilized in OC ITmemory and the insulator may completely block the tie between thechannel of the transistor and the semiconductor body so that thetransistor is a floating device.

Example embodiments are described below with reference to FIGS. 1-31.FIGS. 1-26 illustrate a first embodiment, FIG. 27 illustrates a secondembodiment, and FIGS. 27-31 illustrate applications in electronicsystems.

Referring to FIGS. 1 and 2, such illustrate a top view andcross-sectional side view, respectively, of a semiconductor construction10. The cross-section of FIG. 2 extends through regions which willultimately be active regions.

The construction 10 includes a bulk semiconductor material 12 having anupper surface 13, and includes a dielectric material 14 extending acrossthe upper surface of the semiconductor material.

The bulk semiconductor material 12 may be referred to as a semiconductorbase, and in some embodiments may be referred to as a firstsemiconductor material to distinguish material 12 from othersemiconductor materials that may be formed thereover. The semiconductormaterial 12 may comprise any suitable composition or combination ofcompositions, and may, for example, comprise, consist essentially of, orconsist of monocrystalline silicon lightly doped with background dopant.Such monocrystalline silicon may be part of a silicon wafer. Thesemiconductor base may be referred to as a semiconductor substrate. Theterms “semiconductive substrate,” “semiconductor construction” and“semiconductor substrate” mean any construction comprisingsemiconductive material, including, but not limited to, bulksemiconductive materials such as a semiconductive wafer (either alone orin assemblies comprising other materials), and semiconductive materiallayers (either alone or in assemblies comprising other materials). Theterm “substrate” refers to any supporting structure, including, but notlimited to, the semiconductive substrates described above. Although base12 is shown to be homogenous, it is to be understood that the base maycomprise numerous layers in some embodiments. For instance, base 12 maycorrespond to a semiconductor substrate containing one or more layersassociated with integrated circuit fabrication. in such embodiments,such layers may correspond to one or more of metal interconnect layers,barrier layers, diffusion layers, insulator layers, etc.

The dielectric material 14 may comprise any suitable electricallyinsulative composition or combination of compositions, and may, forexample, comprise, consist essentially of, or consist of one or both ofsilicon dioxide and Silicon nitride. Dielectric material 14 mayalternatively be referred to as electrically insulative material. Thedielectric material may be formed with any suitable processing,including, for example, chemical vapor deposition (CVD).

Referring to FIGS. 3 and 4, dielectric material 14 is patterned to forma plurality of openings 16 extending through the dielectric material tothe underlying semiconductor material of base 12. The patterning ofdielectric material 14 may be accomplished utilizing any suitableprocessing; including, for example, formation of a photolithographicallypatterned photoresist mask (not shown) over material 14, transfer of apattern from the mask to material 14 with one or more suitable etches,and subsequent removal of the mask.

Openings 16 may have any suitable configuration, and in the shownembodiment are substantially elliptical.

Referring to FIGS. 5 and 6, a second semiconductor material 18 is formedover dielectric material 14 and within the openings 16. The openings 16are shown in dashed-line view in FIG. 5 to indicate that the openingsare beneath the second semiconductor material 18.

The second semiconductor material 18 may be formed by epitaxiallygrowing the second semiconductor material from exposed firstsemiconductor material 12 within the openings. The second semiconductormaterial may comprise the same composition as the first semiconductormaterial, or may comprise a different composition. In some embodiments,the first and second semiconductor materials 12 and 18 both comprise,consist essentially of, or consist of silicon; and in some embodimentsmay comprise, consist essentially of, or consist of monocrystallinesilicon.

Second semiconductor material 18 comprises an upper surface 19. Suchupper surface is shown to be substantially planar. The planarization ofthe upper surface may be accomplished by, for example,chemical-mechanical polishing (CMP).

The second semiconductor material 18 is shown in direct contact with thefirst semiconductor material 12, If materials 12 and 18 are the samecomposition as one another, the materials may merge to form a singlematerial. Regardless, material 18 may be considered to be formed indirect contact with material 12.

Referring to FIGS. 7 and 8, patterned masking material 20 is providedover semiconductor material 18, The patterned masking material maycomprise any suitable composition or combination of compositions, andmay, for example, comprise, consist essentially of, or consist of one ormore of photoresist, silicon nitride and silicon dioxide. If thepatterned masking material corresponds to photoresist, the pattern inthe masking material may be formed by photolithographic processing. Ifthe patterned masking material corresponds to one or more compositionsother than photoresist, the masking material may be patterned by formingphotolithographically patterned photoresist over such compositions,transferring a pattern from the photoresist to the compositions with oneor more etches, and then removing the photoresist. In some embodiments,it may be advantageous for masking material 20 to comprise, consistessentially of, or consist of silicon dioxide, as such may eliminate amask-removal step discussed below with reference to FIGS. 12 and 13.

The patterned masking material 20 forms elliptical islands 24 in theshown embodiment, with such islands being spaced from one another bygaps 22. The islands 24 may be utilized to define locations of activeareas within semiconductor material 18, and may he formed in anysuitable configuration. Openings 16 in dielectric material 14 (shown indashed-line view in the top view of FIG. 7) are entirely surrounded byouter peripheries of the islands 24.

Referring to FIGS. 9-11, gaps 22 are extended into semiconductormaterial 18 with an etch of the semiconductor material. The etch may heselective for material 18 relative to dielectric material 14 so that theetch stops on material 14, as shown. An etch is considered selective fora first material relative to a second material if the etch removes thefirst material more rapidly than the second material, which can include,but is not limited to, etches which are 100 percent selective for thefirst material relative to the second material.

The etch of material 18 forms material 18 into a plurality of activeregions 26 beneath the islands 24 of masking material 20. The activeregions are in one-to-one correspondence with the openings 16 in theshown embodiment.

The active regions 26 may be in the form of pedestals. The individualpedestals have a wider region 28 and a narrower stem region 30, forexample, as shown in the cross-section of FIG. 10. The narrow stems passthrough the openings 16 in the dielectric material 14. The cross-sectionof FIG. 10 also shows that portions of dielectric material 14 arebetween the wide upper regions of active regions 26 and the base 12; andin the shown embodiment the only material spacing the wide upper regions28 from base 12 is the dielectric material 14.

In some embodiments, materials 12 and 18 may be considered to togethercorrespond to a semiconductor material comprising a base and pedestalsjoining the base through narrow stems. The description that materials 12and 18 together correspond to a semiconductor material is descriptive ofmaterials 12 and 18 both comprising semiconductor, and may include, butis not limited to, embodiments in which materials 12 and 18 comprise thesame composition as one another.

FIG. 11 shows a cross-section of the active regions 26 substantiallyorthogonal to that of FIG. 10, and illustrates that the active regionshave top surfaces 27 and sidewall surfaces 29 extending downwardly fromthe top surfaces.

Referring next to FIGS. 12 and 13, an insulative material 32 is formedwithin gaps 22 and over active regions 26. The active regions 26 andopenings 16 are shown in dashed-line view in the top view of FIG. 12 toindicate that such are beneath other materials. The materials 32 and 14directly contact one another within gaps 22. in the shown embodiment.

Insulative material 32 may comprise any suitable composition orcombination of compositions, and may, for example, comprise compositionstypically utilized in isolation regions. For instance, insulativematerial 32 may comprise, consist essentially of, or consist of one ormore of silicon dioxide, silicon nitride and. silicon oxynitride. Thepatterned mask 20 (FIGS. 9-11) may be removed prior to formation ofinsulative material 32, or may be left to become part of the insulativematerial. If the insulative material 32 comprises the same compositionas mask 20, the two can merge into a single structure. For instance, insome embodiments both masking material 20 and insulative material 32 maycomprise, consist essentially of, or consist of silicon dioxide.

Insulative material 32 may be referred to as a second dielectricmaterial to distinguish it from the first dielectric material 14.

Referring next to FIGS. 14 and 15, a patterned mask of material 36 isformed over insulative material 32. Material 36 may comprise anysuitable composition or combination of compositions, and may, forexample, comprise photolithographically patterned photoresist.

The patterned mask has a plurality of trenches 40, 42, 44 and 46extending therethrough. The trenches are paired across individual activeregions, as illustrated by the paired trenches 42 and 44 extendingacross individual active regions within the central portion of thefragment of FIGS. 14 and 15.

Referring to FIGS. 16-18, trenches 40, 42, 44 and 46 are extended intomaterials underlying material 36 (FIGS. 14 and 15), and subsequentlymaterial 36 is removed. The trenches may be extended with an etchselective for oxide relative to semiconductor material (for instance,selective for silicon dioxide relative to silicon), in some embodiments.In the shown embodiment, the etch removes exposed portions of first andsecond dielectric materials 14 and 32, Such exposes the upper surfaces27 of semiconductor material 18 within the trenches 40, 42, 44 and 46.

As discussed previously, upper surface 27 corresponds to the topsurfaces of active regions 26. FIG. 18 shows a cross-sectional viewalong the trench 40, and shows that the etch through material 32 (FIG.17) has exposed sidewall surfaces 29 of active regions 26, in additionto exposing the top surfaces 27. In some embodiments, the top surfacesand sidewall surfaces may all be generically referred to as “sides”, andaccordingly the cross-sectional view of FIG. 18 may be considered toshow three sides (corresponding to the top surface 27 and the twosidewall surfaces 29) of the active regions 26 exposed within trench 40.The portions of active regions 26 exposed within the trenches may beconsidered saddle regions (or fin-type regions) 41 due to the non-planartopography of the regions (with such non-planar topography being visiblealong the cross-section of FIG. 18).

FIG. 18 shows that the etch through material 14 has exposed the uppersurface 13 of base 12, in some embodiments, material 14 may comprise acomposition resistant to the etch utilized to etch through material 32so that material 14 is not removed by such etch, and accordingly so thatupper surface 13 of base 12 is not exposed by such etch. For instance,in some embodiments dielectric material 32 may comprise silicon dioxidewhile dielectric material 14 comprises silicon nitride, and the etchthrough material 32 may be selective for silicon dioxide relative tosilicon nitride.

The trenches 40, 42, 44 and 46 formed within material 32 may beconsidered to be patterned within material 32. In the shown embodiment,the trenches are paired across individual active regions 26, asillustrated by the trenches 42 and 44 being paired across a couple ofthe shown active regions.

Referring to FIGS. 19-21, the semiconductor material exposed withintrenches 40, 42, 44 and 46 is subjected to an isotropic etch. Theisotropic etch reduces the height of silicon-containing materials 12 and18 within the trenches as shown in FIGS. 20 and 21. The isotropic etchalso narrows portions of the saddle regions 41 of active regions 26, asshown in FIGS. 19 and 21. The narrowing of the saddle regions exposesupper surfaces of dielectric material 14 adjacent the saddle regions.

The narrowed saddle regions have exposed upper surfaces 47, and exposedsidewall surfaces 49 extending downwardly from the top surfaces. Thepair of sidewall surfaces, together with the top surface, mayalternatively be referred to as three sides.

The base 12 remaining within trenches 40, 42, 44 and 46 has an exposedupper surface 15 which is beneath the elevation of the original. uppersurface 13 (FIG. 18). In embodiments in which material .14 remains overbase 12 after the processing of FIGS. 16-18, the base 12 will beprotected by material 14 and thus not etched by the isotropic etchutilized to narrow the saddle regions 41. Also, in some embodimentssemiconductor materials 12 and 18 may comprise different compositionsrelative to one another so that even if both of materials 12 and 18 areexposed to the isotropic etch that reduces the widths of the saddleregions comprising material 18, such etch may be selective for material18 relative to material 12 so that material 12 is not appreciably etchedduring the reduction in the widths of the saddle regions.

The isotropic etch of the saddle regions may be omitted in embodimentsin which it is desired to maintain the original widths of the saddle.regions.

Referring next to FIGS. 22-24, openings 40, 42, 44 and 46 (FIGS. 19-21.)are lined with insulative materials 50 and 52. The insulative materialsmay comprise any suitable electrically insulative composition orcompositions; and may he the same in composition as one another ordifferent. For instance, either or both of materials 50 and 52 maycomprise, consist essentially of, or consist of one or more of silicondioxide, silicon nitride, silicon oxynitride, and various high-kmaterials (with high-k materials being materials having a dielectricconstant greater than silicon dioxide, such as, for example, tantalumpentoxide).

Insulative material 50 may be formed by providing a layer of material 50across an upper surface of material 32 and within the openings 40, 42,44 and 46, followed by an anisotropic etch of material 50. Subsequently,material 52 may be formed by Oxidation of exposed surfaces ofsemiconductor material 18 within openings 40, 42, 44 and 46 and/or bydeposition of desired material within the openings. In otherembodiments, material 50 may be formed over material 32 and within theopenings, and then patterned so that material 50 remains within theopenings to form an entirety of the liners; and thus material 52 may beomitted.

Conductive material 54 is provided within the lined openings. Theconductive material forms a series of conductive lines 60, 62, 64 and66; Electrically insulative caps 56 are formed over the conductivelines. The conductive lines are labeled in the top view of Fig eventhough such lines are hidden beneath insulative caps 56, The dielectricmaterial 52, conductive material 54 and insulative caps 56 extend aroundsaddle regions 41, and specifically extend along sidewall surfaces 49and top surface 47 of the saddle regions, as shown in FIG. 24.

Conductive material 54 may comprise any suitable composition orcombination of compositions, and may, for example, comprise, consistessentially of, or consist of one or more of various metals (forinstance, tungsten or titanium), metal-containing compositions (forinstance, metal suicides or nitrides) and conductively-dopedsemiconductor materials (for instance, conductively-doped silicon orgermanium).

Insulative caps 56 may comprise any suitable composition or combinationof compositions, and may, for example, comprise, consist essentially of,or consist of one or more of silicon nitride, silicon dioxide andsilicon oxynitride.

Conductive lines 60, 62, 64 and 66 may correspond to wordlines in sonicembodiments. The lines are paired across individual active regions 26,as shown by lines 62 and 64 being paired over the active regions alongthe central portion of the fragment shown in FIGS. 22 and 23.

Referring to FIG. 25, conductivity-enhancing dopant is implanted intoactive regions 26 to form conductively-doped regions 70, 72, 74, 76, 78,80 and 82.

Each active region comprises a pair of conductive lines extendingthereover (for instance, the lines 62 and 64 extending across thecentral active region of the fragment of FIG. 25), and comprises threeconductively-doped regions (for instance, the conductively-doped regions74, 76 and 78 formed within the semiconductor material 18 of the centralactive region of the fragment of FIG. 25). The conductive lines andconductively-doped diffusion regions may together form a plurality oftransistor devices. Specifically, the conductive lines may comprisegates of the devices, and the conductively-doped diffusion regions maycorrespond to source/drain regions gatedly connected to one anotherthrough such gates. in the embodiment of FIG. 25, the conductive linesand conductively-doped diffusion regions are shown to form fourtransistor devices 90, 92, 94 and 96. The devices 92 and 94 are pairedwithin an active region. Three source/drain regions (74, 76 and 78) arewithin such active region. The source/drain region 76 is between thegates of devices 92 and 94, and is shared by the devices 92 and 94. Thesource/drain regions 74 and 78 are outward of devices 92 and 94 andgatedly connected to region 76 through the gates of devices 92 and 94(and specifically through gated control of carrier flow through channelregions beneath such gates). Source/drain region 76 may referred to asan inner region, and source/drain regions 74 and 78 may be referred toas outer regions.

The conductively-doped regions may extend to any suitable depth withinsemiconductor material 18, and in the shown embodiment extend to a depthwhich reaches dielectric material 14.

Capacitors 100, 102, 104 and 106 are formed over base 1.2. Thecapacitors comprise storage node material 105, dielectric material 114,and capacitor plate material 116. The storage node material andcapacitor plate material may be formed of any suitable electricallyconductive composition or combination of electrically conductivecompositions; and may, for example, comprise, consist essentially of, orconsist of one or more of various metals, metal-containing compositions,and conductively-doped semiconductor materials. The dielectric material114 may comprise any suitable electrically insulative composition orcombination of electrically insulative compositions; and may, forexample, comprise, consist essentially of, or consist of one or more ofsilicon dioxide, silicon nitride and various high-k materials.

The storage node material is formed into storage nodes 106, 108, 110,and 112. In the shown embodiment, the insulative material 32 is removedfrom along sides of the active regions 26 to expose such sides, and thestorage nodes extend along the exposed sides of the active regions 26.This can provide for more efficient use of semiconductor real estaterelative to constructions in which the capacitors are formed only overan upper surface of the active regions, In the shown embodiment, thestorage nodes extend along an entirety of the sidewalls of the activeregions. In other embodiments, the storage nodes may extend onlypartially along the sidewalls of the active regions. In someembodiments, material 32 may be left between the active regions and thecapacitors then formed to be entirely over upper surfaces of the activeregions.

The gates of the transistor devices are directly over a portion ofdielectric material 14, and a portion of opening 16. Dashed lines 91 areprovided in FIG. 25 to show the direct overlap of the gate of device 90over a portion of opening 16 and a portion of dielectric material 14.The direct overlap of the gate over a portion of opening 16 enables thetransistor device channel region to be electrically tied with asemiconductor body corresponding to base 12, The direct overlap of thestorage node side of the gate over a portion of dielectric material 14can reduce, and in some embodiments eliminate, leakage from the storagenode back across the access device; and thus may reduce or eliminategate off-state leakage.

The transistor gates may be considered to comprise widths in the showncross-section, with such widths extending from one side of a conductiveline (60, 62, 64 or 66) to the opposing side of the conductive line. Theamount of the width directly over dielectric material 14 may be largeenough to substantially inhibit gate off-state leakage, and yet not solarge as to impair the electrical body tie connection. For example, theamount of the gate width directly over dielectric material 14 may befrom about 25 percent to about 75 percent of the total gate width.

The formation of the outer source/drain regions (in other words, thesource/drain regions electrically coupled with the storage nodes)directly over dielectric material 14 may reduce, or prevent, leakagefrom such source/drain regions directly into the semiconductor bodycorresponding to base 12.

The inner source/drain regions are connected to bitlines 120, 122 and124. Accordingly, the transistors and capacitors of FIG. 25 may beincorporated into a DRAM array.

FIG. 26 shows a cross-section that is parallel to that of FIG. 25, andthat is offset into or out of the page relative to FIG. 25.Specifically, FIG. 25 is a cross-section through the center of a fin(for instance, the fin 41 of FIG. 24), and FIG. 26 is a cross-sectionalong the edge of the fin. Accordingly, FIG. 26 shows the conductivematerial 54 extending down toward dielectric material 14 along the edgeof the fin.

FIG. 27 illustrates an embodiment alternative to that of FIG. 25. Inreferring to FIG. 27, similar numbering will be used as is utilizedabove in describing FIGS. 1-26, where appropriate.

The construction of FIG. 27 comprises the electrically conductivematerial 54 extending within trenches similar to that of FIG. 25, andsuch material may form gates of transistor devices analogously to thegates discussed above with reference to FIG. 25. Source/drain regions70, 72, 74, 76, 78, 80 and 82 are shown proximate such gates.

The embodiment of FIG. 27 differs from that of FIG. 25 in that thetransistor gates formed from lines 60, 62, 64 and 66 in the FIG. 27embodiment are entirely directly over dielectric material 14. Thus, thechannel regions of the transistor devices are electrically isolated fromthe body region of base 12. The transistor devices arc accordinglyelectrically floating devices which may be incorporated into a OCITmemory array.

In the shown embodiment, conductively-doped regions 130, 132, 134 and136 are formed beneath the channel regions. Such conductive regions maybe formed at any suitable processing stage, and may, for example, beformed prior to formation of dielectric material 14 at the processingstage of FIGS. 1 and 2. The conductively-doped regions may be consideredconductive wells which may assist in retaining charge on the floatingtransistors above them, This may reduce a refresh rate associated withthe OCIT memory array.

The various structures described above may be incorporated intoelectronic systems, such as computers, cell phones, clocks, cars,planes, etc.

FIG. 28 illustrates an embodiment of a computer system 400. Computersystem 400 includes a monitor 401 or other communication output device,a keyboard 402 or other communication input device, and a motherboard404. Motherboard 404 may carry a microprocessor 406 or other dataprocessing unit, and at least one memory device 408. Memory device 408may comprise an array of memory cells, and such array may be coupledwith addressing circuitry for accessing individual memory cells in thearray. Further, the memory cell array may be coupled to a read circuitfor reading data from the memory cells. The addressing and readcircuitry may be utilized for conveying information between memorydevice 408 and processor 406. Such is illustrated in the block diagramof the motherboard 404 shown in FIG. 29. In such block diagram, theaddressing circuitry is illustrated as 410 and the read circuitry isillustrated as 412.

Processor device 406 may correspond to a processor module, andassociated memory utilized with the module may comprise DRAM or OCITmemory structures of the types described above.

Memory device 408 may correspond to a memory module, and may compriseDRAM or OCIT memory structures of the types described above.

FIG. 30 illustrates a simplified block diagram of a high-levelorganization of an electronic system 700. System 700 may correspond to,for example, a computer system, a process control system, or any othersystem that employs a processor and associated memory. Electronic system700 has functional elements, including a processor 702, a control unit704, a memory device unit 706 and an input/output (I/O) device 708 (itis to be understood that the system may have a plurality of processors,control units, memory device units and/or I/O devices in variousembodiments). Generally, electronic system 700 will have a native set ofinstructions that specify operations to be performed on data by theprocessor 702 and other interactions between the processor 702., thememory device unit 706 and the I/O device 708. The control unit 704coordinates all operations of the processor 702, the memory device 706and the I/O device 708 by continuously cycling through a set ofoperations that cause instructions to be fetched from the memory device706 and executed. The memory device 706 may include DRAM or OCIT memorystructures of the types described above.

FIG. 31 is a simplified block diagram of an electronic system 800. Thesystem 800 includes a memory device 802 that has an array of memorycells 804, address decoder 806, row access circuitry 808, column accesscircuitry 810, read/write control circuitry 812 for controllingoperations, and input/output circuitry 814. The memory device 802further includes power circuitry 816, and sensors 820, such as currentsensors for determining whether a memory cell is in a low-thresholdconducting state or in a high-threshold non conducting state. Theillustrated power circuitry 816 includes power supply circuitry 880,circuitry 882 for providing a reference voltage, circuitry 884 forproviding a first wordline with pulses, circuitry 886 for providing asecond wordline with pulses, and circuitry 888 for providing a bitlinewith pulses. The system 800 also includes a processor 822, or memorycontroller for memory accessing.

The memory device 802 receives control signals from the processor 822over wiring or metallization lines. The memory device 802 is used tostore data which is accessed via I/O lines. At least. one of theprocessor 822 or memory device 802 may include DRAM or OCIT memorystructures of the types described above.

The various electronic systems may be fabricated in single-packageprocessing units, or even on a single semiconductor chip, in order toreduce the communication time between the processor and the memorydevice(s).

The electronic systems may be used in memory modules, device drivers,power modules, communication modems, processor modules, andapplication-specific modules, and may include multilayer, multichipmodules.

The electronic systems may be any of a broad range of systems, such asclocks, televisions, cell phones, personal computers, automobiles,industrial control systems, aircraft, etc.

In compliance with the statute, the subject matter disclosed herein hasbeen described in language more or less specific as to structural andmethodical features. It is to be understood, however, that the claimsare not limited to the specific features shown and described, since themeans herein disclosed comprise example embodiments, The claims are thusto be afforded full scope as literally worded, and to be appropriatelyinterpreted in accordance with the doctrine of equivalents.

1-67. (canceled)
 68. A semiconductor construction, comprising: asemiconductor material comprising a base and a pedestal extendingupwardly from the base, the pedestal having a wider region joining thebase through a narrower region; a dielectric material over the base, thedielectric material being between the wider region of the pedestal andthe base, and having an opening therein through which the narrowerregion of the pedestal extends; and a transistor comprising gatematerial, the gate material being in the wider region of the pedestaland in the base.
 69. The construction of claim 68 wherein the transistorcomprises a gate dielectric, the gate dielectric being in the widerregion of the pedestal and in the base.
 70. The construction of claim 68wherein the transistor comprises a gate dielectric, the gate dielectriccontacts the pedestal, the dielectric material and the base.
 71. Theconstruction of claim 68 wherein the transistor comprises a pair ofsource/drain regions, only one of the pair of source/drains comprises aportion directly over the opening in the dielectric material.
 72. Theconstruction of claim 68 wherein the transistor comprises a firsttransistor, and further comprising a second transistor having gatematerial, the gate material of the second transistor being in widerregion of the pedestal and in the base.
 73. A semiconductorconstruction, comprising: a semiconductor material comprising a base anda pedestal extending upwardly from the base, the pedestal having a widerregion joining the base through a narrower region; a dielectric materialover the base, the dielectric material being between the wider region ofthe pedestal and the base, and having an opening therein through whichthe narrower region of the pedestal extends; a transistor supported bythe pedestal; and a conductively-doped region in the base and proximatethe transistor to operatively affect the transistor.
 74. Theconstruction of claim 73 wherein the transistor comprises a transistorchannel and wherein the conductively-doped region is directly beneaththe transistor channel.
 75. The construction of claim 73 wherein theconductively-doped region is against the dielectric material.
 76. Theconstruction of claim 73 wherein the transistor comprises a source/drainregion directly over the opening in the dielectric material, thesource/drain region contacting the dielectric material.
 77. Theconstruction of claim 73 wherein the transistor comprises a gate, thegate comprises a width, and wherein the conductively-doped regioncomprises a width substantially the same as the width of the gate. 78.The construction of claim 73 wherein the transistor comprises atransistor channel, and wherein the conductively-doped region is spacedfrom the transistor channel by the dielectric material only.
 79. Theconstruction of claim 73 wherein the transistor comprises a pair ofsource/drain regions, only one of the pair of source/drains comprises aportion directly over the opening in the dielectric material.
 80. Theconstruction of claim 73 wherein the transistor comprises a source/drainregion, the source/drain region is over the opening in the dielectricmaterial and comprises a width that is greater than a width of theopening in the dielectric material.
 81. The construction of claim 73wherein the transistor comprises a first transistor, and furthercomprising a second transistor supported by the pedestal.
 82. Asemiconductor construction, comprising: a semiconductor materialcomprising a base and a pedestal extending upwardly from the base, thepedestal having a wider region joining the base through a narrowerregion; a dielectric material over the base, the dielectric materialbeing between the wider region of the pedestal and the base, and havingan opening therein through which the narrower region of the pedestalextends; and a transistor comprising a gate between a pair ofsource/drain regions in the wider region of the pedestal, the gatecomprising a first portion elevationally level with portions of the pairof source/drain regions and a second portion elevationally above anentirety of the pair of source/drain regions.
 83. The construction ofclaim 82 wherein the transistor comprises a transistor dielectric, andwherein the gate comprises a third portion, the third portion is spacedfrom the opening in the dielectric material by the dielectric materialonly,
 84. The construction of claim 82 wherein the pair of source/drainregions comprises only one source/drain region of the pair over theopening in the dielectric material.
 85. The construction of claim 82wherein an entirety of the dielectric material comprises a planarstructure.